Herbicidal pyridazone derivs - n-(1-(3-trifluoromethylphenyl) -5-halo-pyridazone-6-yl-4)-n'-sulphonyl-(thio)ureas

摘要

Cpds. (I):- (where X is halogen; Y is O or S; R1 is 1-4C alkyl; R2 is H or 1-4C alkyl; and R3 is 1-4C alkyl, cycloalkyl, heterocyclyl or phenyl opt. substd. by halogen, alkyl, alkoxy, haloalkyl or NO2) are prepd. by treating a 1-(3-trifluorophenyl)-5-halo-4-amino-pyridazone-6 with a sulphonyl iso(thio)cyanate and opt. alkylating the product to introduce R2.